Due to increased environmental concerns, many governments have now implemented legislation that requires the conditioning of diesel engine exhaust emissions. This is typically accomplished with a urea injection system that sprays urea into several points within the diesel exhaust system. The urea chemically reacts with the diesel exhaust and catalysts to reduce the objectionable emissions of the vehicle.
This system requires hoses to connect the urea tank, pump and injectors to each other. Fluidic hose fittings are typically assembled to the end of the hoses to connect the hoses for various application and mounting configurations. Additionally, the hose assemblies that carry the urea need to be heated to prevent freezing of the urea in cold climates and the subsequent malfunctioning of the emissions system. In the past, electrically heated hoses have been used that has heater wires wrapped around the hose and encapsulated under an outer hose jacket. The heated hose could contain one or more heating wires that heat up when electrical current is passed through them. However, in the past it has been difficult and expensive to provide heating to the fluidic fittings at the ends of the hoses.
Prior methods of producing heated hose and fitting assemblies have involved time-consuming processes that were not consistently reliable. One prior method involved wrapping the heating wires from the hose around the fitting and securing them to the fitting with self amalgamating tape or other self adhesive material. In an alternative prior method, the heating wires from the hose were wrapped around the fitting and then the wires were covered with shrink tube or mechanical clips. Another prior method involved wrapping the heating wires from the attached hose around the fitting and then covering the fitting and wires with a prefabricated mechanical shell. In yet another prior alternative, a separate heater cartridge was installed over the fitting, then the hose heater wires were terminated to this cartridge. The end of the hose, fitting and heater cartridge are then covered with a pre-fabricated mechanical shell. There remains a need in the art to provide a consistently reliable heated hose and fitting assembly at a commercially viable cost.